As mobile computing devices continue to evolve, the demand for high quality audio reproduction continues to increase. Acoustic echo is a common problem in mobile computing devices that reduces the quality of acoustic audio reproduction. Conventional echo cancellation techniques utilize linear models that often fail to completely remove or adequately reduce the necessary echo components from the signal received at the primary microphone of the mobile computing device. The reason for the degraded performance of the conventional techniques is often distortion introduced by the speaker element of the mobile computing device. The distortion introduced by the speaker may be non-linear, and therefore may not be handled by conventional linear echo canceller algorithms and models. It is desirable, therefore, for mobile computing devices to include a second microphone configured to capture the output of the speaker, including any distortion or inaccuracy introduced by the speaker, and use this signal to reduce non-linear distortion in the audio signal received at the primary microphone. Consequently, there exists a substantial need for techniques to improve non-linear distortion reduction in mobile computing devices.